Best Portable Air Compressor Reviews – Top Picks for 2016
Air compressor is an interesting tool that is mostly used in gas stations, factories and even workshops to inflate tires. The science behind air compressors is very simple: to increase the pressure of air through compression and squeeze it into an enclosed space. In the earlier days, these machines were not as popular as they are today due to their hefty size and noisy motor. The scenario has changed today. The more technology has progressed, the quieter and more efficient these devices have become. The best portable air compressors are a worthy substitute of a bulky centralized power source. If you’re willing to buy one to boost your business, the industry can overwhelm you with an array of exciting options.
Best Portable Air Compressor Models - Our Picks
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The Mechanism behind an Air Compressor
The mechanism of an air compressor might look a little complex on paper but only until you grasp the basic concept of air compression. As I already mentioned before, in order to create pressure, the volume of the air must be reduced through compression. This is achieved mostly by a reciprocating piston or rotating impellers. Piston compressors share a lot of similarity with internal combustion engines in terms of mechanism. Each piston is composed of a cylinder, a connecting rod, a crankshaft and a valve head.
To kick start the function, you’ll need it to connect to a power source. Some top-end models utilize a separate tank for storing the compressed air to maintain a specific range of pressure. The valve head at the top of every compressor houses both the inlet and discharge valves which constantly open and close. The vacuum is created when the piston is pivoted down inside the cylinder. The built up pressure inside the cylinder allows the external pressure to open the inlet valve. The atmospheric air fills the void left by the vacuum and that is when the piston starts compressing it.
Dual Piston Compressors
Dual stage piston compressors are pretty common these days. Their basic function is more or less similar to that of single pistons save one. The double pistons employ two strokes per revolution. In a two stage compressor, one piston thrusts the air into the second cylinder to build up greater pressure. To limit the pressure within a specific range and prevent tank explosion, the compressor dishes out a switch that cuts the power input when the pressure inside the tank reaches the limit. In order to make accurate calculation of the pressure depending on the connected power tool, there are a couple of gauges placed before and after a regulator.
When you will go through the product specs of an air compressor, you will come across terms like “oil-free pump”, “oil lubricated pump”. The way portable air compressors are oiled is a vital aspect to consider during the shopping. Oil lubricated power tools often result in poor-quality in painting or woodworking as the oil enters the air stream and mixes with it. Although a piston ring is attached inside the cylinder to keep the oil and air chamber separated, mixing is still not fully inevitable. Moreover, lubricated pumps can be a chore to maintain. If you had been confused between oil-free and oil-lubricated, now you shouldn’t be.
Air compressors are either powered by gas or electricity. There are no major differences between the functionality of gas powered and electric compressors except a few. Since this article is mainly about portable air compressors, I would like to stress on the factors that aid this particular quality. Gas operated machines houses a gas tank that supplies required energy for the job. If your task requires continuous input of pressure, gas tanks would be an ideal trade for money. However, the hefty design, functional limitation, production of excessive toxic fumes (Gasoline) and lack of proper safety features make it suitable only for heavy-duty industry-level works outdoor.
On the other hand, electric compressors, with all its pros and cons, are still a safer and more convenient choice than its gas-operated counterpart. All you need is a power outlet to get started with the tool. In case the job site is located a little far from the power electric socket, you can always use an extension cord. Electric devises are lightweight, compact and executes a noise-free operation, hardly leads to air pollution, features a “start-stop” switch that automatically shuts down the machine when the pressure inside the tank reaches its saturation point. Electric compressors deliver excellent finishing touch to the work and help in indoor repair jobs as well.
What Are Different Types of Air Compressor Technologies?
Reciprocating Air Compressors
This type of air compressor, as the very name suggests, is operated by reciprocating pistons. The fundamental mechanism used in these compressors is called positive displacement. These are also known as single-stage compressors. Here the piston moves down inside the cylinder to allow the atmospheric air to fill the space above. Dual stage compressors devise a pair of cylinders instead of one.
Rocking Piston Compressors
Rocking piston compressors are nothing but a subset of a standard piston unit. The primary distinguishing factor lies in the procedure to building the pressure. In this case, the air pressure is boosted with the help of an interaction between the piston and the connecting rod. No need of splash lubrication for rocking piston compressors due to the presence of non-metallic rings. Recommended only for small-scale factory and garage works.
Rotary Scroll Air Compressors
In rotary scroll compressors, a blend of a fixed and an orbiting helical element is drawn within the scroll to compress the air. The process is repeated a number of times to create pulsation-free compressed air.
Rotary Screw Compressors
This kind of compressor rotates two mated helical screws placed inside the chamber in order to aggravate the pressure within the chamber by suppressing the volume simultaneously. You need to be careful about the overheating issue constantly in order to run a hassle-free operation. Also remember to keep the oil separated from the compressed air stream before starting the machine.
Rotary Sliding Vane Air Compressors
There are three main components of the motor located inside this compressor-rotor, stator and blades. An intake port and an exhaust port are placed at either ends of the motor. The continuous spinning of the rotor increases the air volume on the intake end and shrinks it on the exhaust end. The rotational acceleration helps keeping the moving blades and vanes safely leaned against the walls of the stator. Like rotary screw compressors, here too the oil and the air need to be separated before using.
Centrifugal Air Compressors
Centrifugal air compressor belongs to a different league of air compressors. Instead of the principle of deplacment, it uses dynamic compression for the job. In simple terms, it simply means increasing the air pressure by means of accelerating the velocity. The in-built impeller inside the device has the capacity of 60000 rotations per minute. Centrifugal compressors have diffusers to slow down the molecules after speeding them up. In order to remove the moisture, they also engineer intercoolers to cool down the air and flush out any fluid stemmed during the process.
Never underestimate the power of compressed air. If wrongly handled, it can result in extremely dangerous consequences at the job site. In order to prevent the occurrence of accidents due to combustion of a compressor, implementing adequate safety measures is imperative. The first thing to is the compressor itself. Check out thoroughly whether the machine is working properly before using for the actual job. Be cautious while oil bathing the pump as well, monitor the oil level to avoid overfilling. You should also make sure the air filter is properly cleaned. If washable, sweep the dirt off the old unit otherwise simply replace with a new one.
Next thing in the to-do list is keeping an eye on the discharge pressure. You should no way allow it to exceed the pressure rating of the tool connected to it. It should either be equal or lower than that. Find out whether the gauges are working fine. The highest-selling portable air compressors in the market have the maximum capacity of the tank clearly written over them. Finally, when you complete your task, shut down the compressor first and then disconnect the power tool from it, never while the former is running.
The Final Word
You must have run across the saying “good things come in small packages” many times, portable air compressors are the perfect example of it. Apart from effortless mobility, there are several other reasons why you should opt for a portable compressor over a non-portable one. By portable, I don’t mean you can carry it along anywhere in your bag pack. It simply means it will be easier to drag it from one place to another in your garage. The inclusion of a compact and highly powerful motor facilitates noise-free operation and guarantees longevity as well. The best air compressor for your pocket is easier to find when your store of knowledge about the product isn’t limited to a few technical terms and brands names.